It is known to provide a material handling system that includes vacuum cups that are adapted to be moved into engagement with an object, such as a substantially flat object or panel or the like, and that lift and move the object to a desired location via a movable support structure. Such vacuum cups or suction cups may be moved into engagement with the object, and a vacuum source may be actuated to create a vacuum between the object and the cup such that the object is retained to the cup as it is transported to the targeted area. An example of such a vacuum cup is disclosed in U.S. Pat. No. 4,662,668, which is hereby incorporated herein by reference. The vacuum cup may include a proximity sensor that determines when the cup has engaged an object and that the object is positioned adjacent to the end of the proximity sensor.
It has been proposed to move the vacuum cups relative to the objects by providing a linear actuator or cylinder at each vacuum cup, such as disclosed in U.S. Pat. No. 4,129,328 issued to Littell. The cylinder may extend and retract to individually move the respective vacuum cup into engagement with the surface of the object. Although such a system may accommodate variations in the surface of the object, the system may include control circuitry and multiple actuators, which may add significantly to the cost and complexity of the system. Also, it is often difficult to properly align or orient the vacuum cups so that the linear actuator or other mounting element is substantially vertically oriented for substantially vertical movement by the support system.
Therefore, there is a need in the art for a material handling system that engages and picks up and moves objects and that overcomes the shortcomings of the prior art.